I am trying to repair a professional S-Video cable. I replaced a connector on one end as one of the pins had broken however, I'm not able to get continuity to one of the signal pins on the other end.
I have checked the solder joints on the new connector and they check-out fine.
Does anyone know of an easy method to detect where the break might be in the cable before I cut the other connector?
I have tried using a tone injector/tracer (for telecoms. cables) however, as the signal is so strong, it couples onto the cable even if is just placed nearby.
Any advice/tips would be grateful.
P.S. Why are there so many unrelated advertising/religious propaganda posts on this thread? It seems that it is not being moderated regularly?
Can you explain why you want to go to all this trouble rather than just buy another one?
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With regards the advertising/religious propaganda thing - most Usenet groups are not moderated, this is one of them. You really haven't done your homework, have you.
One method might be to use time-domain reflectometry. Transmit a fast-rising pulse into one pin on the cable, while monitoring this pin with a fast oscilloscope which can trigger on the rising edge. See how long it takes before you see the effect of a reflection from an open circuit (the voltage at the pin will jump) or a short (the voltage will drop).
Figure an in-cable transmission rate of somewhere on the very rough order of a nanosecond per foot. To work out the actual position of the break, you'll need to know the end-to-end transmission-and- reflection time (e.g. from one of the wires which still works) as well as the end-to-break time. Divide the latter by the former, multiply by the length of the cable, and that'll be where the break is.
This isn't a moderated newsgroup, and it isn't specific to radiobanter. It's an unmoderated USENET newsgroup, fed to radiobanter by a gateway of some sort.
Some of the better USENET providers do filter out / drop the spam postings, and quite a few individuals deliberately drop postings from spam-origin sites (and/or from radiobanter itself).
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Your best and most reliable procedure is to go out and get another cable. The process to find the break can be long, and then you may end up having a splice in the middle of the cable somwhere.
If pro S cables are anything like consumer S cables, I'd toss it and get a new one.
The S cable is the perfect complement to a VHS recorder: The connectors are too small and "fragile", and worse, the coax (?) is so stiff that it's usually impossible to position it in a way that minimizes strain on the connectors.
I have a Cantares UHJ decoder that uses an S cable to connect the power supply to the unit. I hate to think what will happen if the cable or connectors ever break. It's repairable, but I'm not looking forward to it.
I can't imagine a 'pro' S cable; I just spent a few days making a bunch of Y-adapters in both genders to adapt the S connectors on gear to dual RG-59 BNC cable runs. Better gear provides a Y and C BNC connector rather than a DIN style S connector.
I would urge the O.P. to adapt his gear in a similar way; cut the bad cable and use the good end as a start in making the first adapter. I imagine that there are pre-made adapters available, but the cost and delay in shipment may more than justify the time involved in making the adapters (as I have found).
BTW, my spell checker suggests replacing Sommerwerck with Noncommercial ;)
The easy way is with a capacitance meter. Connect between a known good wire and the wire that's suspected of being broken. Measure the capacitance at both ends. If there is a break in the wire, the ratio of the two capacitances is the ratio of the length of broken wire to the total length of the cable. If the capacitance from both ends is equal, the wire is broken in the middle. Compare capacitance with other wire pairs in the bundle. Do NOT measure to the shield, where the capacitance is highly dependent on the wire position inside the bundle.
I also use a TDR (time domain reflectometer), mostly for finding where the mice have chewed their way through ethernet cable. I've built several and have a few pieces of commercial hardware with a built in TDR. The problem is that you'll need a VERY narrow pulse to measure short cables. A telco style TDR is more suitable for cables that are
5 meters or longer.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
The difference between the pro and consumer cables is the price. For overpriced cables, see the various audiophile catalogs.
Now, if I paid $200 to $400 for an S-video cable, I certainly would be interested in repairing it.
There's no such thing as a perfect connector system. I've been complaining about the choice of connectors for 30 years (without much results). For example:
RJ11 telco: Broken tabs, flimsy, not filth proof. RJ45 network: Same as above. RCA phono: Flimsy, difficult to solder, not constant impedance. UHF connector: Impossible to solder, not constant impedance. S-Video: No retention, too stiff cable, tiny pins that break. Cigarette lighter: No retention clip, oversided, low current, ugly. Toslink: Flimsy USB: Far too big. Too easy to break. Originally too stiff cable. Mini/Micro USB: Cannot be cleaned. Too easy to break. PS/2 kbd/mouse: Same as S-video. Too easily broken. D-connectors: Overkill for most applications. Expensive. Apple iPod connector: Too big, too flimsy, too easy to mangle. Magnetic connectors: Great idea, but best used for low power applications instead of Apple power connectors.
2.5/3.5mm jack: Good for earphones and mics, but not for power. HDMI: An improved mini/micro USB connector. Quite good. Lemo: Verrrrrrry expensive but really solid. XL: Huge, monsterous, massive, etc. More suitable for a power connector than for a microphone. AC power plug: Shock hazzard IEC power jack: Not too horrible. No retention, but that's a good thing for most power cord applications. F-connector: Compression type are fine. Crimp ring type fall apart. etc...
Inevitably, I've seen almost every type of connector being used for power. I have a high voltage power supply that uses a UHF connector. Plug in an antenna and fry a few birds. It gets really ugly with gold plated pins, which are really only suitable for dry loads.
Sure. Give an s-video cable to a 3 year old and suggest some exercises.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
I didn't mention that I broke the S connector on my S-VHS VCR. I never got around to fixing it. I'm sure I've broken one or two connectors on other equipment, but they don't come quickly to mind.
You're being overly generous. Methinks they all suck. I forgot to mention that some companies, specifically Motorola Land Mobile, offers new mic and power connectors with every series of radios. The idea is not to improve the connector, but to render all the old accessories instantly obsolete. Special care has obviously been exercised in preventing adapters from working. Even the antenna connectors are often unique, especially on handhelds. In ham radio, the big three (Yeasu, Icom, Kenwood) all use 2.5 and 3.5mm connector pairs for the microphone and handset. No two schemes are the same, or even close. Standards are a good thing... every company should have one.
Extra credit to Dell, Apple and others, for using DisplayPort on their products, instead of the more common HDMI:
There's a 4 cents per connector royalty on HDMI. Just think of the savings.
Be sure to thank the computer gods that only Apple, IBM, and consortiums are allowed to introduce new connectors into computers, or we would face the same instant accessory obsolescence issues found in commerical two-way radio.
S-video connectors will tolerate very little lateral stress. Pull on the cable sideways, and something will bend or break. My problem with such Mini-DIN connectors is the lack of any retention mechanism (i.e. friction, leaf springs, lock, etc). When I pull the hi-fi away from the wall, or out of the rack, the first connectors to unplug themselves are the s-video connectors. On one customers system, I tied string around the cable ends, and tied them to one of the binding posts on the back of the hi-fi, to prevent the cables from falling into the Gordian Knot behind the equipment pile.
Anyway, it's all academic. Soon, we'll all be doing wireless everything and we can forget about most tangled cables and broken connectors. The rest will be fiber, which currently offers a limited number of creative connectors. Power connectors are already fairly standard.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
You can get pretty close to that with a fast risetime step, and a decent scope bandwidth. I've used it to detect where a break was, but (cheat, cheat) I know it would be where the wire was soldered to the connector, I just needed to know which end to do surgery on.
This is a US$5 item. You will expend more than that in time, effort and tooling to make the repair. Buy a new one and be sure that it will work. Buy a couple.
Capacitance meter. Measure the capacitance to ground for each lead at both ends of the cable. The ratio of capcitances will give you the location of the break. For example, if you get 15PF at one end and
40PF at the other on a 36 inch long cable, the break is at: 15 / (15+40) * 36 = 9.8 inches
Yeah, but that's too easy and not any fun. You don't learn anything by simply replacing it.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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